fix(simple-editor): HTML in chatter + library form + expand per-step inline edit

Three fixes from user feedback:

1. Chatter posting raw HTML
   _AUDIT_BODY in migration 19.0.18.8.0 was a plain str with <p>
   tags. message_post escaped it for safety, so the chatter pill
   rendered '<p><strong>...</strong></p>' literally to the recipe
   author. Wrapped in markupsafe.Markup so Odoo recognises it as
   safe HTML. Going forward: ANY message_post body containing HTML
   tags MUST be wrapped in Markup() — most callers already do this,
   the migration script was the outlier.

2. Library template editor showed raw <p> tags
   onOpenLibraryEdit was JSON-cloning the payload directly without
   running description through the existing _htmlToText helper that
   the per-step editor uses. Added the conversion. Save path
   (onSaveLibraryEditor + library_save) already wraps via
   _textToHtml so storage stays HTML-compatible.

3. Per-step inline form was missing critical fields — user had to
   delete + re-add a step to change Type/workflow trigger/parallel/signoff
   onToggleEdit now also captures default_kind, triggers_workflow_state_id,
   parallel_start, requires_signoff into the edit state. onSaveStep
   sends them in the write vals. Added _fpResetStepEdit helper to
   keep open/cancel/save reset paths in sync.

   New per-step form has:
     * Step Type (Default Kind) dropdown — drives workflow milestone
       triggers + step-kind routing (e.g. contract_review opens QA-005)
     * Triggers Workflow State dropdown (Sub 14) — per-step override
     * Parallel Start checkbox (Sub 13)
     * Require QA Sign-off checkbox

   step_write controller endpoint also gained a field whitelist —
   was previously accepting any vals dict from the client (security
   hole + opaque to maintainers).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

fusion_plating/fusion_plating/__manifest__.py

@@ -5,7 +5,7 @@
 
 {
     'name': 'Fusion Plating',
-    'version': '19.0.18.12.3',
+    'version': '19.0.18.12.4',
     'category': 'Manufacturing/Plating',
     'summary': 'Core plating / metal finishing ERP: facilities, processes, tanks, baths, jobs, operators.',
     'description': """